CN1147435A

CN1147435A - Single-forming internal thread milling technology

Info

Publication number: CN1147435A
Application number: CN 95115782
Authority: CN
Inventors: 胡彦群
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-10-06
Filing date: 1995-10-06
Publication date: 1997-04-16

Abstract

The present invention belongs to machining techn and said milling techn is that by using the combined thread cutter comprising drill bit and internal thread cutter, drilling hole and cutting internal thread are completed in one single step in numerically controlled machine tool with designed program. Compared with available method, the said one has improved cutting condition, higher thread precision, 2-3 times higher efficiency and other merits. The said method can produce M4-M14 or larger internal thread.

Description

The once-forming internal thread milling technology

The present invention relates to a kind of once-forming internal thread milling technology, belong to Machining Technology.

At present the female thread machining method that uses in the machining is traditional first preboring bottom outlet, attacks with the hand tapping then or the method for machine tapping tapping.The shortcoming of this method is, the easy wedging cutter of smear metal during tapping under the cutting, so screw tap usually ruptures and causes thread damage.Especially blind threaded tapping is because of the screw tap wedge extremely causes the phenomenon of broken tool and thread damage even more serious.Therefore internal thread machining is compared with other method of surface finish, and expense is high.

The inner screw thread milling once-forming method of introduction of the present invention is that the boring of thread Pilot hole is finished in manufacturing procedure simultaneously with or through hole whorl blind threaded with the milling of internal thread milling cutter.This combinational processing method is called screwed hole milling once shaping technology.When machining internal thread, the accuracy of thread that cuts into this once-forming process technology compares the accuracy of thread height of processing with traditional female thread machining method, thread center's line and end face squareness error are little, work efficiency improves 2 times to 3 times, the problem of the easy wedging cutter of smear metal, screw tap easy fracture when having solved simultaneously with the conventional method machining screw effectively.

Concrete operation principle of the present invention and CONSTRUCTED SPECIFICATION are provided by following embodiment and accompanying drawing:

Fig. 1 is twolip thread milling once-forming cutter structure figure.

Fig. 2 is an inner screw thread milling once shaping technology process drawing.

Fig. 3 is the internal thread part drawing that work in-process is pressed numerical control program processing in the heart.

Twolip screw cutter among Fig. 1 is made by high-speed steel, and it is made of handle of a knife 1, the bit part 2 of front end auger shell line bottom outlet and the screw cutter part 3 of bit part back.The bit part diameter was directly made by the end of processed internal thread.The helix of screw cutter can be dextrorotation, also can be left-handed.Be that cutting movement that cutter carried out is respectively that right cut is cut with left cut and cut therewith accordingly.The course of work of this novel internal thread once-forming processing method was divided into for 7 steps (Fig. 2):

1, lathe starts, the cutter running.

2, cutter sinks to holing to screwed hole needs the degree of depth.

3, cutter slow astern size h, the h value should be greater than processed inside lead.

4, cutter radial feeding one eccentricity value a is so that reach the nominal diameter of internal thread.The size of a value equals half of difference of the nominal diameter of internal thread and bottom diameter.

5, march forward to a helical pitch t in thread center's line rotation at cutter.

6, cutter radially turns back to the center, hole.

7, cutter is by withdrawing from the screwed hole that processes.

In order to realize above-mentioned once-forming inner screw thread milling process, must carry out the control of three-dimensional profile to machining tool.Therefore this novel female thread machining method on Digit Control Machine Tool, use the most suitable.Its feature is:

1, as shown in Figure 1, the bit part 1 of auger shell line bottom outlet, A-A section are represented the drilling inner edge of drill bit, and the C-C section is represented the drilling outside of drill bit.Two inner edges slightly slope inwardly.Two outside angles are about 120 °.Two inner edges and two outsides constitute an obtuse angle.This version that has drill bit and milling cutter feature concurrently helps centering during boring.γ is sharp for the main cutting edge anterior angle, can reduce cutting force, reduces the cutting heat.The helicla flute of milling cutter, the smear metal in the time of can making boring is discharged smoothly.

2, in the screw cutter part, it has two spiral cutter grooves.The thread form of screw cutter annular tooth circle is exactly the thread form of the internal thread that is cut.For the milling cutter thread form is remained unchanged when refacing, it is made into the form of back-off.Because chisel edge approaches zero, cutting edge is sharp, can reduce the cutting resistance that screw thread adds man-hour, reduces heat in metal cutting.During screw cutting, all edge of milling cutter are worked simultaneously, and iron filings can successfully be discharged from two helicla flutes simultaneously, so the cutting operating mode is more far better than tapping.

3, because with drill centers, operations such as auger shell line bottom outlet and screw thread processing merge carries out, and has therefore saved man-hour greatly.

According to the difference of cutter material, the both available high-speed steel manufacturing of cutter, also available carbide alloy manufacturing.The big I of screw cutting is by M4 to M14 or bigger.

This internal thread once-forming processing method, be divided into seven the step finish.Have only the Digit Control Machine Tool that can carry out the three-dimensional location just can finish this work.For this reason, patent of the present invention is an example to process dark M14 of 19 millimeters blind threaded, is provided as that to finish the needed numerical control program of being made up of several blocks of screw chasing circulation as follows:

％ MPF 10

N5 L301N10 G54 G17 T1N15 L300 (internal thread milling cutter, thread Pilot hole diameter Ф 11.9, screw thread M14) N20 G0 X0 Y0 S500 F175 M3 M8N25 GO Z10N30 G1 Z-20N35 G1 Z-17N40 G1 X1.05 Y0N45 G2 X1.05 Y0 Z-19 I-1.05 J0N50 G1 X0 Y0N55 G0 Z100N60 M30

Claims

1, a kind of once-forming internal thread milling technology is characterized in that:

A) once-forming internal thread milling technology system utilizes a kind of novel female thread machining method of combination internal thread milling cutter procedure machining internal thread in accordance with regulations.

B) combination internal thread milling cutter is by handle of a knife 1, and the bit part 2 of front end auger shell line bottom outlet and the screw cutter part of bit part back 3 are formed.

C) procedure of once-forming inner screw thread milling is: lathe starts, the cutter running; Cutter sinks to holing to screwed hole needs the degree of depth; Cutter slow astern size h, the h value should be greater than the helical pitch of processed internal thread; Cutter radial feeding one eccentricity value a, the size of a value equals the nominal diameter of internal thread and half of bottom diameter difference; March forward to a helical pitch t in the cutter rotation and in thread center's line revolution; Cutter radially turns back to the center, hole; Cutter is by withdrawing from the screwed hole that processes.

D) bit part 1 of internal thread milling cutter auger shell line bottom outlet, shown in A-A and C-C section, it has the feature of drill bit and milling cutter concurrently, and its diameter was directly made by the end of processed internal thread.γ is sharp for the main cutting edge anterior angle, can reduce cutting force, reduces the cutting heat.Smear metal when the helicla flute of milling cutter can make boring is discharged smoothly.

E) the screw cutter part 3 of internal thread milling cutter has two spiral cutter grooves.The helix of screw-on cutter can be dextrorotation, also can be left-handed, is accordingly therewith, and the cutting movement that cutter carried out is respectively that right cut is cut with left cut and cut.The thread form of screw cutter annular tooth circle is exactly the thread form of the internal thread that is cut.For the milling cutter thread form is remained unchanged when refacing, it is made into the form of back-off.The milling cutter chisel edge approaches zero, and cutting edge is sharp, can reduce the cutting resistance that screw thread adds man-hour, reduces heat in metal cutting.During screw cutting, all edge of milling cutter are worked simultaneously.Iron filings can be smoothly discharged from two helicla flutes, the cutting operating mode more than the screw tap tapping for well.

According to claim 1 described once-forming internal thread milling technology, it is characterized in that 2, in order to realize internal thread once-forming milling process, must carry out the control of three-dimensional profile to machining tool, therefore this new technology is adapted at using on the Digit Control Machine Tool most.Application can realize that the end mill of three-dimensional profile control and milling machine for sleeping in also can carry out the processing of internal thread once-forming.

3, according to claim 1 described once-forming internal thread milling technology, it is characterized in that, in order to finish internal thread once-forming process carrying out on the Digit Control Machine Tool of three-dimensional profile control, must work out to finishing the screw chasing circulation needed by if the numerical control program of forming in individual block.Now processing one dark 19 millimeters blind threaded part in the heart with work in-process is example, is provided as that to finish the numerical control program that this screw chasing circulation worked out as follows:

％ MPF 10

N5 L301

N10 G54?G17?T1

N15 L300 (internal thread milling cutter, thread Pilot hole diameter of phi 11.9, screw thread M14)

N20 G0?X0?Y0?S500?F175?M3M8

N25 G0?Z10

N30 G1?Z-20

N35 G1?Z-17

N40 G1?X1.05?Y0

N45 G2?X1.05?Y0?Z-19?I-1.05?J0

N50 G1?X0?Y0

N55 G0?Z100

N60 M30